E-cigarette flavorings may impair heart muscle function

Vaping might be a more healthful alternative to smoking, but this does not mean that it is harmless. This is the takeaway message from a new study, which found that some flavorings added to e-cigarette liquids could be damaging for the heart.

The research team identified a number of chemicals used to flavor to electronic cigarette (e-cigarette) liquids — including cinnamon and citrus — that could impair the function of heart muscle cells.

The abstract from the presentation has also been published in the journal Circulation.

Since their introduction to the American market around a decade ago, e-cigarettes have soared in popularity — particularly among youths. According to a 2016 report from the Surgeon General, e-cigarette use among high school students in the United States increased by a whopping 900 percent between 2011 and 2015.

The battery-operated devices are often marketed as a safer alternative to conventional cigarettes, and some research suggests that this is the case. However, scientists are increasingly uncovering the potential dangers of vaping.

‘Striking’ effects

Cardiomyocytes are the cells that make up the heart muscle, and they are responsible for the contractile function of the heart, which enables the organ to pump blood around the body.

“While many flavor chemicals are conventional food additives and generally regarded as safe,” the researchers note, “little is known regarding their impact on human cardiac function. Moreover, how heating/combustion of these compounds affects their toxicity is completely unknown.”

The team identified a number of flavorings that had different effects on cardiomyocyte functions.

They found that cinnamaldehyde, or cinnamon flavoring, prevented the cardiomyocytes from contracting 24 hours after coming into contact with them, while eugenol (clove), citronellol (floral), and limonene (citrus) caused the heart muscle cells to beat faster.

“These effects [from the chemicals] are kind of striking because it suggests that if this compound was interacting with the heart muscle itself, it could do something directly to change how that cell actually functions,” says Nystoriak.

‘Don’t assume that e-cigarettes are harmless’

The researchers note that the flavorings that caused the greatest alterations to cardiomyocytes had the strongest effects when unheated.

However, there are thousands of flavorings for e-cigarette liquids, and the team points out that it is still unclear as to how many of these break down once heated.

One limitation of this study is that the experiments were completed in vivo, so precisely how inhaling the flavorings in e-cigarette liquids might impact cardiomyocyte function needs to be studied further.

Still, commenting on the team’s findings, Matthew L. Springer, Ph.D. — who was not involved in the research but who studies the effects of tobacco smoke on vascular function — says that e-cigarette users should take these results into consideration.

“They should not assume that e-cigarettes are harmless just because they don’t produce smoke. The best thing that you can inhale is clean air.”